


Biology Lessons

by OrpheusUnderneath



Category: InuYasha - A Feudal Fairy Tale
Genre: Alternate Universe - Fantasy, Eventual Romance, Eventual Smut, F/M, M/M, Marine Biology, MerMay, Mermen, Multi, Polyamory, Pre-Poly, Weird Biology
Language: English
Status: In-Progress
Published: 2020-05-25
Updated: 2020-06-08
Packaged: 2021-03-02 19:28:30
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 3,668
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24372049
Author URL: https://archiveofourown.org/users/OrpheusUnderneath/pseuds/OrpheusUnderneath
Summary: Kagome’s a Marine Biologist on a research mission off the coast of Florida, and someone gets caught in her net! She might have to study this new anatomy a little harder. Maybe get more than one subject to study… for science.Updates every Monday!Rated E for later chapters. There will be eventual interspecies sex (merxmerxhuman) featuring *the worm* penis. So, be warned.
Relationships: Higurashi Kagome/InuYasha, Higurashi Kagome/InuYasha/Kouga, Higurashi Kagome/Kouga, InuYasha/Kouga (InuYasha)
Comments: 50
Kudos: 100





	1. Chapter 1

**Author's Note:**

  * For [lemonlush](https://archiveofourown.org/users/lemonlush/gifts).



Kagome Higurashi was tired. 

Of course, 12 hour shifts aboard a boat would do that to you, but the SS Sirenia was the premier research vessel sailing out of Florida, and Kagome counted herself lucky to be a part of the team. They’d been tracking the Portuguese Man ‘o War colonies that were slowly drifting closer to the coast of Florida, but in a surprising turn of events were now drifting further out to sea. 

The whole team was puzzled, but Kagome was truly invested. She was writing her dissertation on the migration and drifting patterns, and this was… unusual. 

Was a stray current pulling them out further? Man o’ War only drifted, so theoretically they shouldn’t be able to move like that on their own…

Looking over the starboard side, Kagome made her rounds and watched the bioluminescent colonies in the distance with a sigh. They’d never get close enough to see them in the daytime because they were just tracking rather than capturing during this mission, but at night it was beautiful. The nearly neon glow as they floated was only amplified by the moonlight, and the still water this far out was truly a sight to behold.

Or at least when the water was actually still, Kagome thought as she heard a massive splashing sound. 

What the hell was that? 

Was a shark caught in the nets below or something? Kagome ran to the side and looked over. Whatever it was, it was big, and it was tangled. 

Resigning herself, she pulled on the lever that cranked the netting up, straining at what was normally a two person job. As the water drained and more and more of the twisted net was revealed, Kagome could only stare in awe. She could only see the tail, but this was no shark. 

Was it some sort of unknown, undiscovered fish? The scales were iridescent and nearly black, with the fins faded from red to black along the tips and white speckling throughout. It was so beautiful…

Wait. 

Was that a hand? 

Oh my God, someone was trapped in the nets with that fish! Someone had gone overboard! She had to get them out, but how…?

“Hold on! I’ll get you out of there. Please be okay!"

Kagome grabbed the lever and lowered the netting onto the deck, hitting her knees and bringing out a pocket knife. It wasn’t great against the industrial rope, but she was able to get a few of the tangles cut away before the giant tail thrashed. She dropped the knife and nicked her hand, blood and pain making her look away from her task to inspect the wound.

And when she looked back up a man was pulling the ropes apart.

Pulling them away from his bare chest. 

From his… tail.

Holy hell, he was the fish with the gorgeous tail. He was a...merman? 

He was staring right at her.

She picked up the knife again to try and cut away more of the net, but he hissed at her and scrambled away, only tangling further.

“Hold still! You’re only making it worse.” 

She grabbed the closest piece of netting and started cutting it away as the merman’s eyes followed her warily, still making a sort of hissing growl under his breath. Kagome held his eyes for a moment before looking down at the tangles again. She’d have to be careful not to cut him for this next bit.

The merman, or whatever he was, was slowly pulling at the ropes along his chest and neck, rending them apart with sharp claws. 

After what seemed like an eternity the ropes were loose enough for him to wriggle out of them and he scrambled away from her toward the boats plexiglass sidewall that was used to observe without the threat of going overboard. He tried to haul himself over, but it was slightly too tall for him to get over without a boost. 

Kagome sighed and put down the knife. Best not to alarm him.

She approached as he tried in vain to pull himself up, and heard the growling get louder as she got closer. Palms up in a soothing manner, she stopped and watched him tense, but then went back to struggling to get out. Their pattern of step forward, growl, stop, and continue happened three more times before she was able to get close enough to tentatively reach a hand out. 

“Hey. I know you probably can’t understand me, but I just wanna help you. Will you let me help you?”

He bared sharp fangs in her direction, but didn’t make any move to bite her as her fingertips touched his bare shoulder. His skin was wet with saltwater, and the cut on her hand stung sharply as she hissed and pulled it away quickly. Her eyes teared up as she stared at the cut, and wiped it on her shorts. 

When she looked back up at him, his golden eyes bore down into hers and then looked down to the hand she was cradling, before looking back to the ship’s side longingly. Kagome knew she had to get him back out there somehow. Maybe she could give him a boost? Would it work if she pushed him up by his waist?

Reaching out to him again yielded far less hissing. 

“I’m going to get you back out there, okay? Just… I’ll figure it out.”

She thought maybe if he leaned on her, with an arm over her shoulders, they could get him over the wall. Biting her lip, she tentatively ran her hand along his arm until she could guide his hand to her shoulder. His eyes were still wary, but he seemed to know that she was trying to help him at least. 

But she couldn’t help but notice just how muscular he was as she tried to lift him up. He was probably two or three times her weight, but there wasn’t an ounce of fat on him. Good god, his biceps were probably as thick as her head, not to mention the abs for days just within her sight.

Looking up to his face was no help from the distraction either. Strong jawline, check. Gorgeous cheekbones, check. Heated golden eyes, check. Luscious silver hair braided down his back, double check. 

But she could hear the way his breathing was slightly labored, see the way his gills were frantically trying to draw in oxygen, and she knew this was no time to just stare. He seemed to have the capacity to breathe air, but just barely. Too long out of the water couldn’t be good for him.

Making another effort and wobbling to her feet, she was barely able to stagger him up to the observation wall and he instantly started trying to pull himself over. She took a moment to watch the muscles of his back move, a smooth glide under flesh that left her breathless.

She was sad to see him go, she realized, but as much as she was fascinated, she knew it was for the best. If anyone else knew about him, they’d lock him up in some science lab underground. No, it was better if he was free, where he belonged.

He turned to her as she watched him pull his fin over the side. A mask of confusion descended over his face as she smiled sadly and made a small wave goodbye. His mouth opened and closed and he seemed to clear his throat.

His rough grumble of “thank you” took her completely by surprise. She couldn’t even process that development before he turned away, back toward the sea.

He slipped off the side of the ship and she heard a large splash. Peering through the glass, she watched the ripple of his descent disappear, and the ocean was still again.


	2. Chapter 2

It had been two nights since she saw him, and now everything seemed boring by comparison. 

How could she possibly focus on anything else when she'd found out that mermen were real?!

She was a marine biologist for god sakes! What she’d give to learn about him, figure out how the mechanics of his tail worked, if he had one set of lungs or two…

But she couldn’t. She’d lost her chance… would probably never see him again.

Kagome sighed softly as she leaned over the railing and looked out at the midnight sky. Her last shift was almost halfway through, since she'd been stuck with the 7pm to 7am rotation 3 nights per week. It sucked, but the days off weren't bad. At least she wasn't burning in the sun every shift.

Gazing out at the horizon line, she felt the boat bob and weave a bit with the wind. There was a storm coming in according to the weather sonar, and they’d need to batten down the hatches soon if they wanted to survive it. But she could just do some minor tightening on her shift since they had a few days before it would hit.

Climbing up the ladder to the second floor, she braced a foot against the knotwork and pulled, making sure the ropework was tight. Just as she was satisfied with it, a large splash in the distance caught her eye, illuminated by the moonlight. 

Leaning over a bit, she caught a flash of silver in the murky deep. Holding her breath, she watched as a head popped up above the water just to his eyes, seemingly searching for something on the boat.

It was him! He was back! 

He swam closer, and she watched as he effortlessly propelled himself closer to the boat, sneakily hiding just under the surface to avoid sight. She wouldn’t have spotted him if she didn’t have the vantage point from above.

He circled the boat, and then a second time. Was he looking for her?

“I’m up here…”

Her voice was just above a whisper but he must have heard her. His cute little ears twitched her way, the frills reminding her of the classical mermaid ears she’d seen in paintings. They seemed so… delicate on such a masculine face.

But then again, everything about him was fascinating and slightly alien. His coloration seemed ombre from black to red and silvery white, making him blend in with the black of the water until his silver hair swirled around. But the upper half of his body… well, there was nothing odd about his bronzed chest.

But this wasn't the time to daydream about handsome otherworldly beings, Kagome. Not when he was right in front of you!

Looking around suspiciously, he slowly swam over before cautiously perching his arms over one of the lifeboats floating beside the hull. The water streaming down his muscles seemed to make her mouth a little dryer. 

“So now that I know you can understand me… Hi. I’m Kagome.” She smiled down as she leaned over the railing. She didn't mean to sound flirty, but it was inevitable. 

“Inuyasha.” His answering grin was infectious, and she felt her own smile turn playful.

Her smile fell as a sudden thought came over her and she climbed down the ladder to the main deck, worried about how open he was being. If anyone else saw him…

“Hey, I want you to know that I won’t hurt you, or tell anyone about your existence, but don’t let anyone else see you, okay? If anyone else knew about you, they’d probably try to catch you or hurt you.” 

Sitting down next to the observation plexiglass, she watched as he came over to float beside her. His fins were beautiful, and she stared awestruck as he laid his head back in the water. The movement of water over his gills drew her eye and he tilted his head toward her in amusement. She was sure she looked like a kid in a candy store, face nearly pressed up against the glass to take in every detail.

“Storm’s coming.”

Kagome wasn’t sure if his short response was because he didn’t know much English or if it was just his personality. Either way, she nodded and he flexed his fins.

“I came to warn you. As a token of my thanks for freeing me.”

“I know, we saw it on the monitors last night. And you don’t have to thank me, I would have freed you either way. You did get caught in our net, after all.” His golden eyes captured hers as he raised an eyebrow, his form bobbing with the water.

“What are you monitoring all the way out here? We’ve never seen humans simply stop out this far, they normally move on quickly.” 

“We’re tracking the Portuguese Man O’ War colonies. They’re not drifting with the current as they usually do.” 

His dark eyebrows seemed to slant downward as a confused look spread across his face.

“What is a Poortugeese Mannowhar?” 

She snickered a bit at his mispronunciation and repeated the words back, pointing at the bioluminescent creatures floating in the distance. Understanding dawned in his eyes as he looked back at her.

“That’s because we’re pushing them back. We call them the Kaitchu. We’re fairly resistant to their stings as adults, but our nymphs… We have to drive them away for our youngs’ safety.”

“So that’s what’s happening!” Kagome couldn’t contain her excitement for a moment, a broad smile sliding across her face before falling minutely. “But that means I won’t be able to write about it in my thesis… I can’t expose your secret.” She blew out a breath in disappointment, looking away into the dark night.

Several moments of silence followed as she looked out at the glowing wildlife beyond. It was comfortable, watching him out of the corner of her eye as he lazily floated.

“Would you like to see them up close?” 

Kagome almost missed his question, with how faint his voice was. 

“How would I? They’re beautiful, but deadly to me if I get stung…” But the longing on her face was plain as day.

“I’ll take you swimming and make sure you’re safe. I’ve taught the tadpoles about them before and kept them away. You’re no different.” His taunting grin made her chuckle, and it made her want to see more of his playful side one day. “Consider it repayment for keeping our secret.”

“You’re sure?” Her excitement seemed to bubble out of her at the thought of seeing the Man O’ War colonies up close, but it was the thought of seeing a merman up close that had her waiting for a response breathlessly. 

“Positive.”


	3. Chapter 3

"Can we go now?" 

"If you want."

Kagome practically vibrated with excitement as she hopped up. It was cute, Inuyasha decided.

She was a strange one, this human. Her features from the top half were pretty. Well that wasn't entirely true. They were gorgeous. Rivaling the mermaids and sirens of legend. 

Not that he'd ever know what a mermaid would look like. By the time he'd come to this clan, their last female had wasted away from the same disease that had taken all of their females. His mother had been gone before he could remember her face, and most female mers had gone soon after. 

Now their last generation was growing up, and they were all male too. 

It was strange. Like magic. Or a curse. And no one knew what was causing it.

But this female. Well, she was funny. Everything seemed to amaze her, and she'd spent most of the time in his presence observing him subtly. 

He didn't mind much. He'd never had a female's interest before, never had the chance to, and he'd found he kind of liked it. Even if she had strange little legs like all humans did.

Legs which she was now baring to his inquisitive gaze. She seemed to have some sort of flimsy garment on below to contain her mammaries and whatever that curve was where a tail should go. 

But despite the legs, she had the right shape, and he could feel himself blushing. Luckily she wouldn't be able to tell through the scales. 

Finally, when she'd laid out her coverings and started to descend the ladder, he realized he'd either have to carry her on his back or belly to belly. 

This could prove disastrous. 

Both positions belied an intimacy that he wasn't sure he was ready for. The question was, paternal carry on the back or mating stance from the front…

Guess he'd go for the back carry.

He watched her jump in from the metal ladder and swam over to her, offering his shoulders for her to grab and float on.

"Hold on tight."

He made an effort to go slow for her, knowing that each push of his fin would jostle her, but it was more difficult than he thought it would be.

Somehow even in this stance, the skin on skin contact had him distracted as he lazily swam the distance to the Kaitchu. Her arms were wrapped around his shoulders and she braced her face against his back as he swam, but it was the feeling of her ankles brushing against his pelvic fin that had him tensing up. 

Those were sensitive. 

Running down the front of his tail, his pelvic fin was a smaller frill in the same bright red as the ombre of his caudal fin. But no one had ever touched those fins except for him. Well, and also Kouga when he was feeling particularly handsy. 

Thinking of Kouga being handsy and the feeling of that brush against his sensitive fin had Inuyasha blushing. He really needed to calm down, or he'd expose himself accidentally. No need for that eel to come out of the cave.

Besides, Kagome was a completely different species. For all he knew she didn't even have the necessary parts.

He was getting sidetracked. 

Slowing down just beyond the edge of the Kaitchu, he felt Kagome's gasp through the skin of his back and smirked at the awestruck look on her face. 

"Can you hold your breath?" 

At her nod, he slowly brought them under the surface, checking that she was okay over his shoulder. Her eyes were wide as he brought her to his chest and they swam underneath the glowing colonies of deadly marine life. She looked up at his face in the bioluminscent light and he couldn't bring himself to look away.

She was beautiful.

Her dark hair swirled all around her face and her eyes shone in the murky depths.

What was this weird feeling? He wanted to… kiss her? What was wrong with him. He was with Kouga, nearly pairbonded. 

And yet when she looked up at him from under her lashes, solely focused on him instead of the reason for their nightly swim… It was like the stars shone brighter. Like the moonlights’ sole purpose was to bask her in it's illumination. 

But then a look of panic started to come over her face. By the way she looked up to the surface, he realized he'd kept her under the water too long. 

"Let me breathe for you." His voice was distorted compared to the surface, but she clearly heard him from the way her eyes widened. 

He leaned forward and sealed his lips over hers, breathing deep through his gills and sharing his breath with her. After a few awkward breaths, her arms came up to circle his shoulders and suddenly he felt like everything was a little too close. 

Her chest and belly pressed to his, the way her legs brushed against his pelvic fin, her hips pressed tightly against his abs…

He needed her to back away, now. 

Peeling himself away, he helped her shift back onto his back and quickly swam around the Kaitchu. The moment they broke the surface tension he heard her gulp in a breath of air greedily, and he quietly started swimming back to the boat.

The air was thick with tension as he pulled up near the metal ladder. She detached from his back and he turned to face her, a blush still apparent on her cheeks from their not-quite kiss. She opened her mouth and then closed it, and he felt the same struggle she was, not knowing what to say.

"Will I see you again?" She broke the silence like a bubble bursting. "My next shift to be alone at night isn't until 3 nights from now… But if you want I can sneak away the day after tomorrow, when everyone eats in the middle of the day. Normally I’m sleeping then so no one should notice that I’m gone." 

Against his better judgment, he nodded. She piqued his interest like no one else had. Well, no one but Kouga. 

At the thought of his almost lover, he inwardly cringed. How was he going to face him tomorrow for guard duty when he'd been out all night with Kagome? 

Even though they hadn't done anything truly over the line, he still felt guilty. He liked Kouga, really liked him.

But there was this odd feeling creeping up his chest every time he saw Kagome. He'd been coming to watch her every night since she freed him from the net, and though this was only the second time they'd been face to face, he felt like he knew her in ways he shouldn't have paid attention to. 

The way she hummed softly as she did her tasks on deck, her favorite way to tie back her hair, the look of longing on her face when she stared out at the ocean…

He should tell her that they shouldn't do this. Tell her that they were different species… that he had someone back at the colony who was interested…

But all he could muster was a soft goodnight as she climbed the ladder and waved at him from the main deck. He waited until she went below, and then with a soft click, everything was still.


End file.
